A plurality of electronic control units (ECUs) are normally installed in a motor vehicle. Such ECUs are operative to control at least one target device/function installed in the motor vehicle in accordance with corresponding control programs and control data stored therein.
Specifically, each of the ECUs is programmed to execute the control programs using the control data, thereby controlling the corresponding at least one target device/function.
Such control programs stored in an ECU may be required to be reprogrammed with new versions thereof due to, for instance, software bugs in the control programs. Similarly, control data associated with the control programs and stored in an ECU may be required to be reprogrammed with new control data due to, for example, errors in the control data.
A remote reprogramming technology has been used for such data reprogramming. An example of the conventional remote reprogramming technology is disclosed in Japanese Patent Application Publication No. H05-195859.
The remote reprogramming technology is designed to remotely reprogram control programs and control data associated therewith stored in an ECU through a radio communication network, such as cellular networks.
The remote reprogramming technique prevents the drivers (users) from driving their motor vehicles for data reprogramming, making it possible to rapidly repair the bugs and/or errors in the control programs and/or the control data.
Specifically, in the remote reprogramming technique, a data reprogramming unit of a reprogramming station is provided and managed by a manufacture of motor vehicles which are integrated with an ECU.
In response to a request for data reprogramming of an ECU (target ECU) of one motor vehicle (target motor vehicle), the data reprogramming unit accesses the target ECU through cellular networks so as to inform the target ECU of a reprogramming instruction. Next, the data reprogramming unit sends, to the target ECU through the cellular networks, data for use in reprogramming. This data for use in reprogramming will be referred to as “reprogramming data” hereinafter.
On the other hand, the target ECU of each of the motor vehicles receives the reprogramming instruction sent from the reprogramming station, and provides for the receipt of the reprogramming data. When the reprogramming data is sent thereto from the data reprogramming unit, the target ECU of the target motor vehicle receives the reprogramming data. Thereafter, the target ECU reprograms at least one of control programs and control data associated therewith based on the received reprogramming data; these control programs and control data having been stored in the target ECU.